Safety device for searchlights



June 29 1926. 1,590,896

F. w. LNSTADT SAFETY DEVICE FOR SEARCHLIGHTS Filed March 15, 1923 iii Patented June 29, 1926.

FRANK W LINSTADT, OF LOS ANGELES, CALIFORNIA.

SAFETY DEVICE FOR SEAR-CHLIGHTS.

Application filed March 15, 1923.

My invention relates to and has for its purpose the provision of a safety device or automatic cut-out for are lights which operates to disrupt the supply of current to the electrodes and the automatic feeding means for the electrodes before one of the electrodes consumed to the extent that the are occurs in injurious relation to the supporting means for the electrode whereby burning of the electrode support is positively prevented.

It also a purpose of my invention to provide an automatic cu" extremely era le construc tion which can be readily applied to one of the electrode supports to sustain a fusible strip at the inner end of the su port so as to be fused when the active end of the corresponding electrode is in proximity to the end of the support.

Although I have herein shown and described only one form of automatic cut-outembodying my invention, it to be understood that various changes and modifications may be made herein without departing from the spirit of the invention and the spirit and scope of the appended claims.

In the accompanying drawings,

Figure l a view showing in side eieva tion and partly in section on are light of the Sperry type having applied thereto one form of automatic cut-out vn'ibodyii'ig my invention.

Fig. 2 is a top plan view of the are light shown in Fig. l and with a diagrammatic showing of the circuit for the are light in the manner in which the cut-out device is interposed in the circuit.

Fig. 3 is a detailed perspec ive view of the cut-out device shown in the preceding views.

leferrinp' specifically to the drawings in which similar reference characters refer to similar parts my invention in its present embodiment comprises a supporting elementwhich in the present instance is in the form of a block of suitable insulating material having one side thereof of concave form as indicated at 15 so as to permit of its application to an electrode support or casing. Brackets 16 are formed with off-set ends 17 provided with openings through which binding posts 18 extend for the double purpose of securing the brackets to the block 15 and for connecting conductors to the brackets. These brackets, as shown Serial No. 625,292.

in Fig. 3. are substantially of L-shaped form, with the vertical portions thereof disposed in spaced relation to the block l5 and formed with i'ipturned es reniitieslil which provide seats for the reception of the opposite ends of a strip oi. fusible material. Set screws extend through the extremities 19 so as to engage the ends of the strip 20 for securing the latter against accidental displacement from the brackets.

In Figs. 1 and 2 1 have shown conven tional form of are light including a positive electrode 22 and a negative electrode 23. These two electrodes are mounted in sup ports 2i and 25, respectively, and the sup ports in turn are mounted on standards 26 and 2?, respectively. "he supports and in the present instance are shown of cylindrical formation with the exception that their confronting ends are of conical form so as to provide relatively small openings from which the active ends of the electrodes 22 and 23 project. The standard 27 is adapted to be automatically moved through the medium of the motor 28 shown diagrammatically in Fig. 2, and for the purpose of effecting an automatic adjustment of the negative electrode 23 so that during the c011- summation of the positive electrode 22, the negative electrode will continue to occupv arcing position as will be understood by those skilled in the art. I

In the applied position of the cut-out de vice, the block 15 is suitably secured to the support 2%. the concave side 15 conforming to the curvature of the support. The positioning of the block 15 is such that the fusible strip 20 is supported by the brackets 16 in overlying relation to the electrode 22 and at the apex of the conicalv end of the support 241-.

As shown diagrauunatically in Fig. 2, the electrodes 22 and 23 are included in a cir- 23. wire 82, motor 28. negative wire 30.

In the operation of the are light, the motor 28 operates to move the standard 27 to effect, as hereinbefore described, an automatic adjustment of the negative electrode 23, and when the positive electrode has been consumed to the point that its active end is disposed adjacent the conical end of the support 24-, the flame rising from the are between the electr des touches the fusible strip 20 thereby melting the latter and breaking the electric connection between the brackets 16. As a. result the circuit for the are light including; the electrodes and the motor 28 is disrupted therebydiscontinuin the supply of current to the electrodes and motor and consequently extinguishing the arc and discontinuing the adjustn'ient of the negative electrode.

By virtue of the positioning of the fusible strip 20, it will be clear that such strip is fused by the arc thuue before the reaches the support 24!: so that the possibility of the are burning or in any injuring the support is positively prevented. It will be clear that the circuit for the are light may be restored to its normal condition by removing the disconnected sections of the fusible strip and substituting therefor a continuous fusible strip so that an electric con nection between the bracket 16 will again be formed.

What I claim is:

A. safety device for search lights comprising a block of insulating material mounted upon the support of the positive electrode of an arc lamp brackets of conducting material formed with onset ends provided with openings, binding posts inserted through the openings and connecting the brackets to the block and for connecting conductors to the brackets, said brackets having clownturned ends spaced apart, and a strip of fusible material connecting the downturned ends, so that when the safety device is mounted upon the are lamp the fusible strip will be near the arc and when the positive carbon becomes too short the will fuse the strip and break the circuit. i

In testimony whereof I have signed my name to this specification.

FRANK W. LINSTA T. 

